JP7306451B2 - Resist underlayer film-forming composition containing alicyclic compound-terminated polymer - Google Patents

Description

The present invention relates to compositions for use in lithographic processes in semiconductor manufacturing, particularly for state-of-the-art (ArF, EUV, EB, etc.) lithographic processes. The present invention also relates to a method of manufacturing a substrate with a resist pattern to which the resist underlayer film is applied, and a method of manufacturing a semiconductor device.

2. Description of the Related Art Conventionally, microfabrication by lithography using a resist composition has been performed in the manufacture of semiconductor devices. In the microfabrication, a thin film of a photoresist composition is formed on a semiconductor substrate such as a silicon wafer, exposed to actinic rays such as ultraviolet rays through a mask pattern on which a device pattern is drawn, and developed. This is a processing method in which the substrate is etched using the obtained photoresist pattern as a protective film to form fine unevenness corresponding to the pattern on the substrate surface. In recent years, the degree of integration of semiconductor devices has advanced, and the actinic rays used in addition to the conventionally used i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm) have reached the maximum. Practical use of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for fine processing of the tip. Along with this, the diffuse reflection of actinic rays from the semiconductor substrate and the influence of standing waves have become serious problems. In order to solve this problem, a method of providing a bottom anti-reflective coating (BARC) between the resist and the semiconductor substrate has been widely studied. The antireflection film is also called a resist underlayer film. As such an antireflection film, many investigations have been made on an organic antireflection film made of a polymer or the like having a light-absorbing site because of its ease of use.
Patent Document 1 discloses a composition for forming a resist underlayer film used in a lithography process for manufacturing a semiconductor device, which contains a polymer having a repeating unit structure having a polycyclic aliphatic ring in the main chain of the polymer. Patent Document 2 discloses a composition for forming a resist underlayer film for lithography containing a polymer having a specific structure at its end.

JP 2009-093162 A International Publication No. 2013/141015

Properties required for the resist underlayer film include, for example, no intermixing with the resist film formed on the upper layer (insolubility in the resist solvent), and a faster dry etching rate than the resist film. mentioned.
In the case of lithography involving EUV exposure, the line width of the formed resist pattern is 32 nm or less, and the resist underlayer film for EUV exposure is formed thinner than before. When forming such a thin film, it is difficult to form a defect-free and uniform film because pinholes, aggregation, and the like are likely to occur due to the influence of the substrate surface, the polymer used, and the like.
On the other hand, when forming a resist pattern, in the development step, a solvent capable of dissolving the resist film, usually an organic solvent, is used to remove the unexposed portion of the resist film, leaving the exposed portion of the resist film as a resist pattern. is sometimes adopted. In such a negative development process, improvement of the adhesion of the resist pattern is a major issue.
In addition, it is possible to suppress deterioration of LWR (Line Width Roughness, line width roughness, line width fluctuation (roughness)) at the time of resist pattern formation, form a resist pattern having a good rectangular shape, and improve resist sensitivity. Needs improvement.

An object of the present invention is to provide a composition for forming a resist underlayer film capable of forming a desired resist pattern, and a method for forming a resist pattern using the resist underlayer film-forming composition, which solves the above problems. .

The present invention includes the following.
[1] A composition for forming a resist underlayer film, which contains an aliphatic ring whose carbon-carbon bond may be interrupted by a hetero atom and may be substituted by a substituent at the end of the polymer, and which further contains an organic solvent. .
[2] The composition for forming a resist underlayer film according to [1], wherein the aliphatic ring is a monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms.
[3] The resist underlayer film-forming composition according to [2], wherein the polycyclic aliphatic ring is a bicyclo ring or a tricyclo ring.
[4] The resist underlayer film-forming composition according to any one of [1] to [3], wherein the aliphatic ring has at least one unsaturated bond.
[5] the substituents include a hydroxy group, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 10 carbon atoms and a carboxy The composition for forming a resist underlayer film according to any one of [1] to [4], which is selected from groups.

[6] The resist underlayer film-forming composition according to any one of [1] to [5], wherein the polymer has at least one structural unit represented by the following formula (3) in its main chain.

(In formula (3), A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and Q ₁ represents a divalent organic group. and _m1 and _m2 each independently represent 0 or 1.)
[7] The composition for forming a resist underlayer film according to [6], wherein in the formula (3), _Q1 represents a divalent organic group represented by the following formula (5).

(Wherein, Y represents a divalent group represented by the following formula (6) or (7).)

(wherein R ₆ and R ₇ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group is substituted with at least one selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms; or R ₆ and R ₇ may be bonded together to form a ring having 3 to 6 carbon atoms together with the carbon atoms bonded to R ₆ and R _7. )
[8] The resist underlayer film-forming composition according to any one of [1] to [7], wherein the polymer further contains a disulfide bond in its main chain.
[9] The resist underlayer film-forming composition according to any one of [1] to [8], further comprising a curing catalyst.
[10] The resist underlayer film-forming composition according to any one of [1] to [9], further comprising a cross-linking agent.
[11] A resist underlayer film characterized by being a baked product of a coating film made of the resist underlayer film-forming composition according to any one of [1] to [10].
[12] A step of applying the resist underlayer film-forming composition according to any one of [1] to [10] on a semiconductor substrate and baking it to form a resist underlayer film, and applying a resist on the resist underlayer film. A patterned substrate, comprising the steps of coating and baking to form a resist film, exposing the resist underlayer film and the semiconductor substrate coated with the resist, and developing and patterning the resist film after exposure. manufacturing method.
[13] forming, on a semiconductor substrate, a resist underlayer film comprising the resist underlayer film-forming composition according to any one of [1] to [10];
forming a resist film on the resist underlayer film;
a step of forming a resist pattern by irradiating the resist film with light or an electron beam and then developing;
forming a patterned resist underlayer film by etching the resist underlayer film through the formed resist pattern;
a step of processing a semiconductor substrate with the patterned resist underlayer film;
A method of manufacturing a semiconductor device, comprising:

In the resist underlayer film-forming composition for lithography of the present invention, the terminal of the polymer (also referred to as polymer) contained in the resist underlayer film-forming composition is a fatty acid in which the carbon-carbon bond may be interrupted by a hetero atom. characterized by being capped with an aliphatic ring that may be further substituted with a tricyclic ring and an aliphatic ring that may be substituted by A composition containing a compound (curing catalyst). The composition for forming a resist underlayer film for lithography of the present application, having such a constitution, can form a resist pattern having a favorable rectangular shape (pattern collapse does not occur), suppress deterioration of LWR when forming a resist pattern, and improve sensitivity. improvement can be achieved.

≪Explanation of terms≫
Terms used in the present invention have the following definitions unless otherwise specified.

The "alkyl group having 1 to 10 carbon atoms" includes methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, s-butyl group, t -butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl- n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl-n-propyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2 -ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1, 1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n- butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2 -trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group , 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2 -dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclo propyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2 , 3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl-cyclopropyl group, 2-ethyl-3 -methyl-cyclopropyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icodecyl group and the like.

The "alkoxy group having 1 to 20 carbon atoms" includes methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentyloxy group, 1-methyl-n-butoxy group, 2-methyl-n-butoxy group, 3-methyl-n-butoxy group, 1,1-dimethyl-n-propoxy group, 1,2-dimethyl- n-propoxy group, 2,2-dimethyl-n-propoxy group, 1-ethyl-n-propoxy group, n-hexyloxy group, 1-methyl-n-pentyloxy group, 2-methyl-n-pentyloxy group , 3-methyl-n-pentyloxy group, 4-methyl-n-pentyloxy group, 1,1-dimethyl-n-butoxy group, 1,2-dimethyl-n-butoxy group, 1,3-dimethyl-n -butoxy group, 2,2-dimethyl-n-butoxy group, 2,3-dimethyl-n-butoxy group, 3,3-dimethyl-n-butoxy group, 1-ethyl-n-butoxy group, 2-ethyl- n-butoxy group, 1,1,2-trimethyl-n-propoxy group, 1,2,2-trimethyl-n-propoxy group, 1-ethyl-1-methyl-n-propoxy group, and 1-ethyl-2 -methyl-n-propoxy group, cyclopentyloxy group, cyclohexyloxy group, norbornioxy group, adamantyloxy group, adamantanemethyloxy group, adamantaneethyloxy group, tetracyclodecanyloxy group, tricyclodecanyloxy group and the like. .

As the "acyloxy group having 1 to 10 carbon atoms", the following formula (20):

（式（２０）中、Ｚは水素原子、又は上記「炭素原子数１～１０のアルキル基」中の「炭素原子数１～９のアルキル基」を表し、＊は上記「脂肪族環」との結合部分を表す。）で表されるものを言う。

(In the formula (20), Z represents a hydrogen atom, or an “alkyl group having 1 to 9 carbon atoms” in the above “alkyl group having 1 to 10 carbon atoms”, and * represents the above “aliphatic ring”. Represents the connecting part of ).

The "alkenyl group having 3 to 6 carbon atoms" includes 1-propenyl group, 2-propenyl group, 1-methyl-1-ethenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2- methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1-propenyl group, 1-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3 -Pentenyl group, 4-pentenyl group, 1-n-propylethenyl group, 1-methyl-1-butenyl group, 1-methyl-2-butenyl group, 1-methyl-3-butenyl group, 2-ethyl-2 -propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3 -methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2 -Pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group , 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl- 3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2 -dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group , 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1 -butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1- butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1-methyl-1-ethyl-2 -propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl group, 1-i-propyl-2-propenyl group, 1-methyl-2-cyclopentenyl group, 1-methyl-3-cyclopentenyl group, 2-methyl-1-cyclopentenyl group, 2-methyl-2-cyclopentenyl group, 2-methyl-3-cyclopentenyl group, 2-methyl-4-cyclopentenyl group, 2-methyl-5-cyclopentenyl group, 2-methylene-cyclopentyl group, 3-methyl-1-cyclopentenyl group, 3-methyl-2-cyclopentenyl group, 3 -methyl-3-cyclopentenyl group, 3-methyl-4-cyclopentenyl group, 3-methyl-5-cyclopentenyl group, 3-methylene-cyclopentyl group, 1-cyclohexenyl group, 2-cyclohexenyl group and 3- A cyclohexenyl group and the like can be mentioned.

Examples of the "alkylthio group having 1 to 6 carbon atoms" include methylthio, ethylthio, propylthio, butylthio, pentylthio and hexylthio groups.

A "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The "arylene group having 6 to 40 carbon atoms" includes a phenylene group, o-methylphenylene group, m-methylphenylene group, p-methylphenylene group, o-chlorophenylene group, m-chlorophenylene group, p-chloro phenylene group, o-fluorophenylene group, p-fluorophenylene group, o-methoxyphenylene group, p-methoxyphenylene group, p-nitrophenylene group, p-cyanophenylene group, α-naphthylene group, β-naphthylene group, o -biphenylylene group, m-biphenylylene group, p-biphenylylene group, 1-anthrylene group, 2-anthrylene group, 9-anthrylene group, 1-phenanthrylene group, 2-phenanthrylene group, 3-phenanthrylene group, 4-phenanthrylene group and 9 -phenanthrylene group.

<Resist Underlayer Film Forming Composition>
In the resist underlayer film-forming composition of the present application, at the end of the polymer contained in the resist underlayer film-forming composition, an aliphatic ring whose carbon-carbon bond may be interrupted by a hetero atom, and further substituted with a substituent. contains a good aliphatic ring and further contains an organic solvent.

The carbon-carbon bond may be interrupted by a heteroatom means that the carbon-carbon bond of the aliphatic ring of the present application includes -O- and -S- bonds.

An optionally substituted aliphatic ring means that all or part of the hydrogen atoms in the aliphatic ring of the present application are, for example, a hydroxy group, a straight-chain or branched-chain alkyl having 1 to 10 carbon atoms alkoxy group having 1 to 20 carbon atoms, acyloxy group having 1 to 10 carbon atoms and carboxy group.

The aliphatic ring is preferably a monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms.

Examples of "monocyclic or polycyclic aliphatic ring having 3 to 10 carbon atoms" include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cyclohexene, cycloheptane, cyclooctane, cyclononane, cyclodecane, spirobicyclopentane , bicyclo[2.1.0]pentane, bicyclo[3.2.1]octane, tricyclo[3.2.1.0 ^2,7 ]octane, spiro[3,4]octane, norbornane, norbornene, tricyclo[ 3.3.1.1 ^3,7 ]decane (adamantane) and the like.

The polycyclic aliphatic ring is preferably a bicyclo ring or a tricyclo ring.
Among these, bicyclo rings include norbornane, norbornene, spirobicyclopentane, bicyclo[2.1.0]pentane, bicyclo[3.2.1]octane, spiro[3,4]octane and the like.
Among these, tricyclo rings include tricyclo[3.2.1.0 ^2,7 ]octane and tricyclo[3.3.1.1 ^3,7 ]decane (adamantane).

The aliphatic ring preferably has at least one unsaturated bond (eg double bond, triple bond). The aliphatic ring preferably has 1 to 3 unsaturated bonds. The aliphatic ring preferably has one or two unsaturated bonds. The unsaturated bond is preferably a double bond.

Specific examples of the "aliphatic ring in which the carbon-carbon bond may be interrupted by a hetero atom and optionally substituted by a substituent" include the compounds described below, attached to the ends of the polymer by a method known per se. It is induced by reacting.

The polymer preferably has at least one structural unit represented by the following formula (3) in its main chain.

(In formula (3), A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and Q ₁ represents a divalent organic group. and _m1 and _m2 each independently represent 0 or 1.)
In formula (3), Q ₁ preferably represents a divalent organic group represented by formula (5) below.

(Wherein, Y represents a divalent group represented by the following formula (6) or (7).)

(wherein R ₆ and R ₇ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group is substituted with at least one selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms; or R ₆ and R ₇ may be bonded together to form a ring having 3 to 6 carbon atoms together with the carbon atoms bonded to R ₆ and R _7. )

"C3-C6 rings" include cyclopropane, cyclobutane, cyclopentane, cyclopentadiene and cyclohexane.

It is preferred that the polymer further contains disulfide bonds in the main chain.

It is preferable that the polymer contains an arylene group having 6 to 40 carbon atoms which may be substituted with a substituent. The meanings of the substituents are the same as those described above.

The weight average molecular weight of the polymer is, for example, 2000-50000.

Examples of the monomer forming the structural unit represented by the above formula (3) in which m ₁ and m ₂ represent 1 include epoxy groups represented by the following formulas (10-a) to (10-k). a compound having two

That is, diglycidyl 1,4-terephthalate, diglycidyl 2,6-naphthalenedicarboxylate, 1,6-dihydroxynaphthalenediglycidyl, diglycidyl 1,2-cyclohexanedicarboxylate, 2,2-bis(4-hydroxyphenyl)propanedi glycidyl, 2,2-bis(4-hydroxycyclohexane)propane diglycidyl, 1,4-butanediol diglycidyl, diglycidyl monoallyl isocyanurate, diglycidyl monomethylisocyanurate, diglycidyl 5,5-diethylbarbiturate, 5,5 - dimethylhydantoin diglycidyl, but are not limited to these examples.

Examples of monomers forming structural units represented by the above formula (3) in which m ₁ and m ₂ are 0 are represented by the following formulas (11-a) to (11-s): a compound having two carboxyl groups, hydroxyphenyl groups or imide groups, and an acid dianhydride;

i.e. isophthalic acid, 5-hydroxyisophthalic acid, 2,4-dihydroxybenzoic acid, 2,2-bis(4-hydroxyphenyl)sulfone, succinic acid, fumaric acid, tartaric acid, 3,3′-dithiodipropionic acid, 1,4-cyclohexanedicarboxylic acid, cyclobutanoic dianhydride, cyclopentanoic dianhydride, monoallyl isocyanuric acid, 5,5-diethylbarbituric acid, diglycolic acid, acetonedicarboxylic acid, 2,2'-thiodi Glycolic acid, 4-hydroxyphenyl 4-hydroxybenzoate, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,3-bis(carboxymethyl )-5-methyl isocyanurate, 1,3-bis(carboxymethyl)-5-allyl isocyanurate, but are not limited to these examples.

A monomer (difunctional) that forms a structural unit represented by the formula (3) where m ₁ and m ₂ are 1, and a structure represented by the formula (3) where m ₁ and m ₂ are 0 The copolymerization ratio (charged weight ratio) with the monomer (bifunctional) forming the unit is, for example, 1:2 to 2:1.
Furthermore, the weight ratio of the monomer (the site that mainly reacts with the polymer is monofunctional) for deriving the aliphatic ring bonded to the end of the polymer of the present application to the total amount of the above monomers is, for example, 20: 1 to 5: 1. .
"Functionality" is a concept that focuses on the chemical attributes and chemical reactivity of substances. Functional groups are assumed to have their own physical properties and chemical reactivity, but in this application, they can be combined with other compounds. Refers to a reactive substituent.
The repeating number of the structural unit represented by formula (3) is, for example, in the range of 5 or more and 10,000 or less.

Examples of the organic solvent contained in the resist underlayer film-forming composition of the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, Propylene Glycol Monomethyl Ether, Propylene Glycol Monoethyl Ether, Propylene Glycol Monomethyl Ether Acetate, Propylene Glycol Propyl Ether Acetate, Toluene, Xylene, Methyl Ethyl Ketone, Methyl Isobutyl Ketone, Cyclopentanone, Cyclohexanone, Cycloheptanone, 4-Methyl-2-Pene Tanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3-ethoxy methyl propionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more.
Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone and the like are preferred. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.
The ratio of the organic solvent to the resist underlayer film-forming composition of the present invention is, for example, 50% by mass or more and 99.9% by mass or less.
The polymer contained in the resist underlayer film-forming composition of the present invention is, for example, 0.1% by mass to 50% by mass relative to the resist underlayer film-forming composition.

The resist underlayer film-forming composition of the present invention may contain, in addition to the polymer and the organic solvent, a cross-linking agent and a cross-linking catalyst (curing catalyst) which is a compound that accelerates the cross-linking reaction. When the composition for forming a resist underlayer film of the present invention excluding the organic solvent is defined as the solid content, the solid content includes the polymer and additives such as cross-linking agents and cross-linking catalysts added as necessary. The proportion of the additive is, for example, 0.1% by mass to 50% by mass, preferably 1% by mass to 30% by mass, based on the solid content of the resist underlayer film-forming composition of the present invention.

Examples of cross-linking agents contained as optional components in the resist underlayer film-forming composition of the present invention include hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril (tetramethoxy methyl glycoluril) (POWDERLINK® 1174), 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1,3-bis (hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, 1,1,3,3-tetrakis(methoxymethyl)urea, and 3,3′,5,5′-tetrakis(methoxy) methyl) 4,4'-biphenol. When the cross-linking agent is used, the content of the cross-linking agent is, for example, 1% to 50% by mass, preferably 5% to 30% by mass, relative to the polymer.

The curing catalyst (crosslinking catalyst) contained as an optional component in the composition for forming a resist underlayer film of the present invention includes, for example, p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfone acid), pyridinium-p-hydroxybenzenesulfonic acid, pyridinium-trifluoromethanesulfonic acid, cyclohexyl p-toluenesulfonate, morpholine, p-toluenesulfonate, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4 -Hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, sulfonic acid compounds and carboxylic acid compounds such as hydroxybenzoic acid. When the cross-linking catalyst is used, the content of the cross-linking catalyst is, for example, 0.1% by mass to 50% by mass, preferably 1% by mass to 30% by mass, based on the cross-linking agent.

A surfactant may be further added to the composition for forming a resist underlayer film of the present invention in order to further improve coatability against surface unevenness without generating pinholes, striations, and the like. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, and polyoxyethylene nonylphenol ether. Polyoxyethylene alkyl allyl ethers such as polyoxyethylene/polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, etc. sorbitan fatty acid esters, polyoxyethylene sorbitan such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Nonionic surfactants such as fatty acid esters, F-top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., trade names), Megafac F171, F173, R-30 (manufactured by Dainippon Ink Co., Ltd., commercial products name), Florado FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., trade name), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd., trade name), etc. and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The blending amount of these surfactants is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the total solid content of the resist underlayer film-forming composition of the present invention. These surfactants may be added singly or in combination of two or more.

<Resist underlayer film>
The resist underlayer film according to the present invention can be produced by applying the resist underlayer film-forming composition described above onto a semiconductor substrate and baking the composition.
Semiconductor substrates to which the resist underlayer film-forming composition of the present invention is applied include, for example, silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride. be done.
When using a semiconductor substrate having an inorganic film formed on its surface, the inorganic film is formed by, for example, an ALD (atomic layer deposition) method, a CVD (chemical vapor deposition) method, a reactive sputtering method, an ion plating method, or a vacuum deposition method. It is formed by a spin coating method (spin on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium oxynitride film, a tungsten film, a gallium nitride film, and a gallium arsenide film. is mentioned.
The composition for forming a resist underlayer film of the present invention is applied onto such a semiconductor substrate by a suitable coating method such as a spinner or a coater. Thereafter, a resist underlayer film is formed by baking using a heating means such as a hot plate. Baking conditions are appropriately selected from a baking temperature of 100° C. to 400° C. and a baking time of 0.3 minutes to 60 minutes. Preferably, the baking temperature is 120° C. to 350° C. and the baking time is 0.5 minutes to 30 minutes, and more preferably the baking temperature is 150° C. to 300° C. and the baking time is 0.8 minutes to 10 minutes.
The film thickness of the resist underlayer film to be formed is, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm). ) ~ 0.05 µm (50 nm), 0.002 µm (2 nm) ~ 0.05 µm (50 nm), 0.003 µm (1 nm) ~ 0.05 µm (50 nm), 0.004 µm (4 nm) ~ 0.05 µm (50 nm) , 0.005 μm (5 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.03 μm (30 nm), 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm). If the baking temperature is lower than the above range, the crosslinking may be insufficient. On the other hand, if the baking temperature is higher than the above range, the resist underlayer film may be thermally decomposed.

<Method for Manufacturing Patterned Substrate, Method for Manufacturing Semiconductor Device>
A method of manufacturing a patterned substrate includes the following steps. Usually, it is manufactured by forming a photoresist layer on a resist underlayer film. The photoresist formed by coating and baking on the resist underlayer film by a method known per se is not particularly limited as long as it is sensitive to the light used for exposure. Both negative and positive photoresists can be used. positive photoresist composed of novolac resin and 1,2-naphthoquinonediazide sulfonic acid ester; A chemically amplified photoresist comprising a low-molecular compound that decomposes to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and a binder having a group that decomposes with an acid to increase the alkali dissolution rate. There are chemically amplified photoresists composed of low-molecular-weight compounds and photoacid generators that are decomposed by acid to increase the rate of alkali dissolution of photoresists, and resists containing metal elements. Examples include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley, PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., AR2772 (trade name) and SEPR430 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd., and the like. Also, for example, Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

Exposure is performed through a mask (reticle) for forming a predetermined pattern, and for example, i-ray, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet) or EB (electron beam) is used. is preferably applied for EUV (extreme ultraviolet) exposure. An alkaline developer is used for development, and the development temperature is selected from 5° C. to 50° C. and the development time is appropriately selected from 10 seconds to 300 seconds. Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, secondary amines such as di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; Aqueous solutions of alkalis such as quaternary ammonium salts, pyrrole, cyclic amines such as piperidine, and the like can be used. Further, an alcohol such as isopropyl alcohol or a nonionic surfactant may be added in an appropriate amount to the aqueous alkali solution. Preferred developers among these are quaternary ammonium salts, more preferably tetramethylammonium hydroxide and choline. Furthermore, a surfactant or the like can be added to these developers. It is also possible to use a method of developing with an organic solvent such as butyl acetate instead of the alkaline developer, and developing the portion where the rate of alkali dissolution of the photoresist is not improved. Through the above steps, a substrate having the resist patterned thereon can be manufactured.

Next, using the formed resist pattern as a mask, the resist underlayer film is dry-etched. At that time, when the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed, and when the inorganic film is not formed on the surface of the semiconductor substrate used, the semiconductor substrate is exposed. expose the surface. After that, the substrate is processed by a method known per se (dry etching method, etc.), and a semiconductor device can be manufactured.

EXAMPLES Next, the content of the present invention will be specifically described with reference to Examples, but the present invention is not limited to these.
The weight average molecular weights of the polymers shown in Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 and 2 in this specification are the results of measurement by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC apparatus manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions and the like are as follows.
GPC column: Shodex KF803L, Shodex KF802, Shodex KF801 [registered trademark] (Showa Denko KK)
Column temperature: 40°C
Solvent: Tetrahydrofuran (THF)
Flow rate: 1.0 ml/min Standard sample: polystyrene (manufactured by Tosoh Corporation)

<Synthesis Example 1>
N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Kasei Co., Ltd.) as polymer 1 7.88 g, monoallyl isocyanuric acid (manufactured by Shikoku Kasei Co., Ltd.) 5.03 g, 5-norbornene-2-carvone 1.45 g of acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.65 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 66.60 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 3000 and a polydispersity of 2.8 in terms of standard polystyrene. The structure present in polymer 1 is shown in the formula below.

<Synthesis Example 2>
As polymer 2, N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Kasei Co., Ltd.) 7.88 g, monoallyl isocyanuric acid (manufactured by Shikoku Kasei Co., Ltd.) 5.07 g, 3-cyclohexene-1-carvone 1.34 g of acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.66 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 66.60 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 2500 and a polydispersity of 2.2 in terms of standard polystyrene. The structure present in polymer 2 is shown in the formula below.

<Synthesis Example 3>
As polymer 3, N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Kasei Kogyo Co., Ltd.) 7.95 g, monoallyl isocyanuric acid (manufactured by Shikoku Kasei Kogyo Co., Ltd.) 5.07 g, 5-norbornene-2,3 - 1.74 g of dicarboxylic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.66 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 66.60 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 2500 and a polydispersity of 2.2 in terms of standard polystyrene. The structure present in polymer 3 is shown in the formula below.

<Synthesis Example 4>
As polymer 4, N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Kasei Co., Ltd.) 7.88 g, monoallyl isocyanuric acid (manufactured by Shikoku Kasei Co., Ltd.) 5.07 g, cyclohexane-1-carboxylic acid ( Tokyo Kasei Kogyo Co., Ltd.) and 0.63 g of ethyltriphenylphosphonium bromide (Tokyo Kasei Kogyo Co., Ltd.) were added to 66.60 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 2500 and a polydispersity of 2.2 in terms of standard polystyrene. The structure present in polymer 4 is shown in the formula below.

<Synthesis Example 5>
As polymer 5, N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Kasei Kogyo Co., Ltd.) 7.73 g, monoallyl isocyanuric acid (manufactured by Shikoku Kasei Kogyo Co., Ltd.) 4.94 g, 7-oxabicyclo [2. 2.1] 1.71 g of hept-5-ene-2,3-dicarboxylic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.64 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), It was dissolved in 66.60 g of propylene glycol monomethyl ether. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 2500 and a polydispersity of 2.0 in terms of standard polystyrene. The structure present in polymer 5 is shown in the formula below.

<Synthesis Example 6>
As polymer 6, N,N-diglycidyl-5,5-dimethylhydantoin (manufactured by Shikoku Kasei Kogyo Co., Ltd.) 7.20 g, 5-hydroxyisophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 4.95 g, 5-norbornene-2 - 1.33 g of carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.54 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 39.19 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 2500 and a polydispersity of 2.2 in terms of standard polystyrene. The structure present in polymer 6 is shown in the formula below.

<Synthesis Example 7>
As polymer 7, 25.00 g of monoallyl diglycidyl isocyanurate (manufactured by Shikoku Chemical Industry Co., Ltd.), 14.72 g of diethyl barbituric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 5-norbornene-2,3-dicarboxylic anhydride 2.91 g (manufactured by Tokyo Chemical Industry Co., Ltd.) and 1.64 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 89.73 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 3000 and a polydispersity of 2.3 in terms of standard polystyrene. The structure present in polymer 7 is shown in the formula below.

<Synthesis Example 8>
Monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.) 25.00 g, dithiodipropanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 15.86 g, adamantane carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) as polymer 8 4.80 g and 1.13 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 57.12 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 5000 and a polydispersity of 2.3 in terms of standard polystyrene. The structure present in polymer 8 is shown in the formula below.

<Synthesis Example 9>
Monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.) 25.00 g as polymer 9, dithiodipropanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 15.86 g, 5-norbornene-2-carboxylic acid (Tokyo Chemical Industry Co., Ltd. Co., Ltd.) and 1.13 g of tetrabutylphosphonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) were added to 57.12 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 5,000 and a polydispersity of 2.5 in terms of standard polystyrene. The structure present in polymer 9 is shown in the formula below.

<Comparative Synthesis Example 1>
Monoallyl diglycidyl isocyanurate (manufactured by Shikoku Chemical Industry Co., Ltd.) 21.90 g, diethyl barbituric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 12.17 g, lauric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) as polymer 10 4 .67 g and 0.56 g of ethyltriphenylphosphonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) were added to 89.73 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 3000 and a polydispersity of 2.2 in terms of standard polystyrene. The structure present in polymer 10 is shown in the formula below.

<Comparative Synthesis Example 2>
As polymer 11, monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.) 25.00 g, dithiodipropanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 15.86 g, tetrabutylphosphonium bromide (Tokyo Chemical Industry Co., Ltd.) ) was added to 57.12 g of propylene glycol monomethyl ether and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 24 hours to obtain a polymer solution. GPC analysis revealed that the obtained polymer had a weight average molecular weight of 5,000 and a polydispersity of 4.3 in terms of standard polystyrene. The structure present in polymer 11 is shown in the formula below.

(Preparation of resist underlayer film)
(Example 1)
The above Synthesis Examples 1-9, Comparative Synthesis Examples 1-2, polymer, cross-linking agent, curing catalyst, and solvent were mixed in the proportions shown in Table 1, and filtered through a 0.1 μm fluororesin filter to form a resist lower layer. A solution of each film-forming composition was prepared.
In Table 1, PL-LI is tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd.), PyPTS is pyridinium-p-toluenesulfonic acid, PyPSA is pyridinium-p-hydroxybenzenesulfonic acid, and propylene glycol monomethyl ether acetate is PGMEA and propylene glycol monomethyl ether are abbreviated as PGME. Each addition amount is shown in parts by mass.

(Elution test into photoresist solvent)
The resist underlayer film-forming compositions of Examples 1 to 11 and Comparative Examples 1 and 2 were applied onto a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205° C. for 60 seconds to obtain a film with a thickness of 5 nm. These resist underlayer films are immersed in a mixed solution of propylene glycol monomethyl ether/propylene glycol monomethyl ether = 70/30, which is a solvent used for photoresist, and when the film thickness change is 1 Å or less, it is good, 1 Å or more. The results are shown in Table 3 as defective. Only Comparative Example 1 showed failure.

(Measurement of water contact angle)
The resist underlayer film-forming compositions of Examples 1 to 11 and Comparative Examples 1 and 2 were applied onto a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205° C. for 60 seconds to obtain a film with a thickness of 5 nm. The contact angle of water on these resist underlayer films was measured by the droplet method using a fully automatic contact angle meter DM-701 (manufactured by Kyowa Interface Science Co., Ltd.).

(Resist patterning evaluation)
[Formation of resist pattern by KrF exposure]
DUV-30J (manufactured by Nissan Chemical Industries, Ltd.) was applied as an antireflection film onto a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205° C. for 60 seconds to obtain a film with a thickness of 18 nm. The resist underlayer film-forming compositions of Examples 1 to 6, Example 8, and Comparative Examples 1 and 2 were applied onto the silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205° C. for 60 seconds to obtain a resist underlayer film with a thickness of 5 nm. On the resist underlayer film, SEPR-430 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a positive resist solution for KrF excimer laser was spin-coated and heated at 100° C. for 60 seconds to form a KrF resist film. The resist film was exposed under predetermined conditions using a KrF excimer laser exposure apparatus (NSR S205C manufactured by Nikon Corporation). After exposure, post-exposure heating was performed at 110° C. for 60 seconds, and a 2.38% tetramethylammonium hydroxide aqueous solution (manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name NMD-3) was used as a photoresist developer. Puddle development was performed for 60 seconds. The obtained photoresist pattern was evaluated as good if large pattern peeling did not occur.

[EUV exposure test]
The resist underlayer film-forming compositions of Examples 9, 10 and Comparative Example 2 of the present invention were spin-coated on a silicon wafer and heated at 215° C. for 1 minute to form a resist underlayer film (thickness: 5 nm). formed. An EUV resist solution (methacrylate resin-based resist) was spin-coated on the resist underlayer film, heated, and exposed under the condition of NA=0.33 Dipole using an EUV exposure apparatus (manufactured by ASML, NXE3300). After exposure, post-exposure baking (PEB, 100° C. for 60 seconds) was performed, cooling to room temperature on a cooling plate, alkali development and rinsing were performed to form a resist pattern on the silicon wafer. Evaluation was performed based on whether or not a line and space (L/S) of 16 nm was formed. In all cases of Examples 9, 10 and Comparative Example 2, 16 nm L/S pattern formation was confirmed. In addition, the exposure dose for forming a 16 nm line/32 nm pitch (line and space (L/S = 1/1) is taken as the optimum exposure dose, and the exposure dose (EOP) at that time is shown.Furthermore, the roughness of the line width at that time ( LWR) is shown in Table 5. In Examples 9 and 10, compared with Comparative Example 2, an improvement in LWR was observed.

[EUV exposure test]
The composition for forming a resist underlayer film of Example 1 of the present invention was spin-coated on a silicon wafer and heated at 215° C. for 1 minute to form a resist underlayer film (thickness: 5 nm). Furthermore, an EUV resist solution (methacrylate resin-based resist) is spin-coated thereon and heated at 130° C. for 1 minute to form an EUV resist film. Exposure was performed under the conditions of 0.33 and Dipole. After exposure, post-exposure heating (PEB, 110° C. for 1 minute) is performed, cooled to room temperature on a cooling plate, developed with an organic solvent developer (butyl acetate) for 60 seconds, rinsed, and a resist pattern is formed. formed.
Using the compositions obtained in Examples 3, 6 to 8, and Comparative Example 2, resist patterns were formed in the same procedure.
The evaluation was made by confirming the pattern shape by observing the cross section of the pattern to determine whether or not lines and spaces of 44 nm pitch and 22 nm can be formed.
In the observation of the pattern shape, "good" means that the shape is between the footing and the undercut and there is no significant residue in the space, and "collapsed" means that the resist pattern is peeled off and collapsed. An unfavorable state in which the tops or bottoms of the resist patterns are in contact with each other was evaluated as "bridge". Table 6 shows the results obtained.

The resist underlayer film-forming composition according to the present invention is a composition for forming a resist underlayer film capable of forming a desired resist pattern, a method for producing a substrate with a resist pattern using the resist underlayer film-forming composition, a semiconductor A method of manufacturing a device can be provided.

Claims (13)

Formation of a resist underlayer film containing an aliphatic ring which may contain -O-, -S- bonds between carbon-carbon bonds and may be substituted with a substituent at the end of the polymer, and which further contains an organic solvent. A composition comprising:
Monomers for forming structural units contained in the main chain of the polymer include diglycidyl 1,4-terephthalate, diglycidyl 2,6-naphthalenedicarboxylate, 1,6-dihydroxynaphthalenediglycidyl, and 1,2-cyclohexanedicarboxylic acid. Diglycidyl acid, 2,2-bis(4-hydroxyphenyl)propanediglycidyl, 2,2-bis(4-hydroxycyclohexane)propanediglycidyl, 1,4-butanedioldiglycidyl, diglycidyl monoallylisocyanurate, monomethylisocyanurate monomer (I) selected from the group consisting of diglycidyl acid, diglycidyl 5,5-diethylbarbiturate, and 5,5-dimethylhydantoin diglycidyl; acid, 2,2-bis(4-hydroxyphenyl)sulfone, succinic acid, fumaric acid, tartaric acid, 3,3'-dithiodipropionic acid, 1,4-cyclohexanedicarboxylic acid, cyclobutanoic dianhydride, cyclopentanoic acid dianhydride, monoallyl isocyanuric acid, 5,5-diethylbarbituric acid, diglycolic acid, acetonedicarboxylic acid, 2,2'-thiodiglycolic acid, 4-hydroxybenzoic acid-4-hydroxyphenyl, 2,2 -bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,3-bis(carboxymethyl)-5-methylisocyanurate, and 1,3-bis(carboxymethyl) )-5-allyl isocyanurate selected from monomers (J) selected from the group consisting of
The monomer (K) for inducing an aliphatic ring bonded to the polymer terminal is selected from the group consisting of compounds of the following formula,

The charged weight ratio of the monomer (K) for deriving an aliphatic ring bonded to the terminal of the polymer to the sum of the monomers (I) and (J) for forming the structural unit contained in the polymer main chain is 20. : 1 to 5:1 resist underlayer film-forming composition. 2. The composition for forming a resist underlayer film according to claim 1 , wherein the monomer (I) and the monomer (J) are charged in a weight ratio of 1:2 to 2:1 . The monomer (K) is

The composition for forming a resist underlayer film according to claim 1 or 2, which is selected from the group consisting of : The monomer (K) is

The composition for forming a resist underlayer film according to claim 1 or 2 , which is selected from the group consisting of : The monomer (K) is

The composition for forming a resist underlayer film according to claim 1 or 2 , which is selected from the group consisting of : The monomer (K) is

The composition for forming a resist underlayer film according to claim 1 or 2 , which is selected from the group consisting of : Claims 1-6 , wherein the monomer (J) is selected from the group consisting of 5-hydroxyisophthalic acid, 3,3'-dithiodipropionic acid, monoallyl isocyanuric acid, and 5,5-diethylbarbituric acid. The composition for forming a resist underlayer film according to any one of items 1 to 3 . 8. The resist underlayer film-forming composition according to claim 1, wherein the monomer (I) is selected from the group consisting of diglycidyl monoallylisocyanurate and 5,5-dimethylhydantoindiglycidyl . The resist underlayer film-forming composition according to any one of claims 1 to 8, further comprising a curing catalyst. 10. The resist underlayer film-forming composition according to any one of claims 1 to 9, further comprising a cross-linking agent. A resist underlayer film characterized by being a baked product of a coating film comprising the resist underlayer film-forming composition according to any one of claims 1 to 10. A step of applying the resist underlayer film-forming composition according to any one of claims 1 to 10 on a semiconductor substrate and baking to form a resist underlayer film, applying a resist onto the resist underlayer film and baking it. A method for manufacturing a patterned substrate, comprising the steps of forming a resist film, exposing the resist underlayer film and the semiconductor substrate coated with the resist, and developing and patterning the resist film after exposure. A step of forming a resist underlayer film comprising the resist underlayer film-forming composition according to any one of claims 1 to 10 on a semiconductor substrate;
forming a resist film on the resist underlayer film;
a step of forming a resist pattern by irradiating the resist film with light or an electron beam and then developing;
forming a patterned resist underlayer film by etching the resist underlayer film through the formed resist pattern;
a step of processing a semiconductor substrate with the patterned resist underlayer film;
A method of manufacturing a semiconductor device, comprising: